Sinha P K, Prasad K N
In Vitro. 1977 Aug;13(8):497-501. doi: 10.1007/BF02615142.
Adenosine 3',5'-cyclic monophosphate (cyclic AMP) phsophodiesterase activity in mouse neuroblastoma cells in culture markedly increased during exponential growth and reached a maximal level at confluency; whereas guanosine 3'5'-cyclic monophosphate (cyclic GMP) phosphodiesterase activity only slightly but significantly increased under a similar experimental condition. The increase in cyclic AMP phosphodiesterase activity was blocked by both cycloheximide and dactinomycin, whereas the increase in cyclic GMP phosphodiesterase was blocked by only cycloheximide. When the confluent cells were replated at low density, the cyclic nucleotide phosphodiesterase activity decreased; however, when they were plated at high cell density which equaled confluency, the enzyme activity did not decrease. Unlike cyclic AMP phosphodiesterase activity, cyclic GMP phosphodiesterase activity did not change significantly in prostaglandin E1-treated cells, but decreased in cells treated with the inhibitor of phosphodiesterase. Like cyclic AMP phosphodiesterase activity, cyclic GMP phosphodiesterase activity also did not change in cells treated with serum-free medium, X-irradiation, sodium butyrate and 6-thioguanine.
培养的小鼠神经母细胞瘤细胞中，3',5'-环磷酸腺苷（环磷酸腺苷）磷酸二酯酶活性在指数生长期显著增加，并在汇合时达到最高水平；而在类似实验条件下，3',5'-环磷酸鸟苷（环磷酸鸟苷）磷酸二酯酶活性仅略有但显著增加。环磷酸腺苷磷酸二酯酶活性的增加被放线菌酮和放线菌素D阻断，而环磷酸鸟苷磷酸二酯酶活性的增加仅被放线菌酮阻断。当汇合细胞以低密度重新接种时，环核苷酸磷酸二酯酶活性降低；然而，当它们以等于汇合密度的高细胞密度接种时，酶活性并未降低。与环磷酸腺苷磷酸二酯酶活性不同，环磷酸鸟苷磷酸二酯酶活性在前列腺素E1处理的细胞中没有显著变化，但在用磷酸二酯酶抑制剂处理的细胞中降低。与环磷酸腺苷磷酸二酯酶活性一样，环磷酸鸟苷磷酸二酯酶活性在无血清培养基、X射线照射、丁酸钠和6-硫鸟嘌呤处理的细胞中也没有变化。
